Magnetic Field Exposure Modulates the Anti-Inflammatory Efficiency of Minocycline in Rats with Peripheral Acute Inflammation.

BACKGROUND AND OBJECTIVE: Microglial activation in spinal cord is key contributor and its inhibition by Minocycline (MCN) can result in anti-inflammatory actions. Effect of pulsed magnetic field (PMF) in living system is a very complex process and many biological and cellular processes can play key roles. In this study aimed to reveal the roles of PMF exposure on anti-inflammatory potentials of MCN treatment by evaluating the inflammatory profiles of either inflamed site or spinal cord. METHODS: In this study, we investigated the anti-inflammatory effects of PMF, MCN or their combination treatments in rats with carrageenan (CG)-induced peripheral inflammation by examining the cardinal signs, hyperalgesia, allodynia, edema and fever. The levels of various inflammation markers (tumor necrosis factor-α), interleukin (IL)-1ß, IL-6, IL-17, IL-4, IL-10, C-C motif chemokine ligand3 (CCL3), C-X-C motif chemokine ligand1 and myeloperoxidase were also measured in paw and spinal cord tissues. RESULTS: CG induced inflammation caused edema, fever, and hypersensitivities. MNC or PMF treatments ameliorated these responses by suppressing pro-inflammatory markers in both inflamed paw and spinal cord. Although anti-hypersensitive, anti-edematous and anti-pyretic actions of MCN or PMF, in combined treatments PMF exposure decreased the anti-hyperalgesic and anti-allodynic actions of MCN treatment. These may be associated with decreases in IL-4 and IL-10 levels and an increase in CCL3 level of spinal cord tissues. CONCLUSION: Present findings support that MCN or PMF has anti-inflammatory properties duo to the down-regulating central microglial and/or peripheral inflammatory markers. Our data showed here, for the first time, PMF exposure may suppress the anti-hypersensitive actions of MCN by modulating microglia function/phenotype and microglial markers.

Effects of extremely low-frequency electromagnetic field exposure on the skeletal muscle functions in rats.

The aim of the present study was to systematically investigate the effects of chronic exposure to extremely low-frequency electromagnetic field (ELF-EMF) on electrophysiological, histological and biochemical properties of the diaphragm muscle in rats. Twenty-nine newly weaned (24 days old, 23-80 g) female (n = 15) and male (n = 14) Wistar Albino rats were used in this study. The animals were randomly divided into two groups: the control group and the electromagnetic field (EMF) group. The control group was also randomly divided into two groups: the control female group and the control male group. The EMF exposure group was also randomly divided into two groups: the ELF-EMF female group and the ELF-EMF male group. The rats in the ELF-EMF groups were exposed for 4 h daily for up to 7 months to 50 Hz frequency, 1.5 mT magnetic flux density. Under these experimental conditions, electrophysiological parameters (muscle bioelectrical activity parameters: intracellular action potential and resting membrane potential and muscle mechanical activity parameter: force-frequency relationship), biochemical parameters (Na+, K+, Cl- and Ca+2 levels in the blood serum of rats; Na+-K+ ATPase enzyme-specific activities in muscle tissue; and free radical metabolism in both muscle tissue and serum) and transmission electron microscopic morphometric parameters of the diaphragm muscle were determined. We found that chronic exposure to ELF-EMF had no significant effect on the histological structure and mechanical activity of the muscle and on the majority of muscle bioelectrical activity parameters, with the exception of some parameters of muscle bioelectrical activity. However, the changes in some bioelectrical activity parameters were relatively small and unlikely to be clinically relevant.

Anti-inflammatory properties of Liposome-encapsulated clodronate or Anti-Ly6G can be modulated by peripheral or central inflammatory markers in carrageenan-induced inflammation model.

Overproduction of inflammatory markers by immune cells, such as macrophages and neutrophils, is one of the main reasons for many inflammatory conditions and inhibiting or suppressing of their production by cell depletion may provide new therapeutic targets or approaches to prevent a variety of inflammatory conditions. In this study, we examined the possible effects of anti-Ly6G-mediated systemic neutrophil depletion and liposome-encapsulated clodronate (LEC)-mediated systemic macrophage depletion on the inflammatory signs (thermal hyperalgesia, mechanical allodynia, oedema and fever) and measured the levels of various inflammation markers (tumour necrosis factor-α (TNF-α), interleukins (IL)-1ß, IL-4, IL-10, macrophage inflammatory protein-1 alpha (MIP-1α/CCL3) and myeloperoxidase (MPO) in paw and spinal cord tissues in carrageenan (CG)-induced hindpaw inflammation model in rats. CG injection into the paw caused inflammation characterized by redness, swelling, heat and pain hypersensitivities. Anti-Ly6G or LEC significantly ameliorated the pain behaviours, and decreased the oedema and fever. Efficacies of anti-Ly6G or LEC on inflammatory responses changed depend on the degree of inhibition in inflammatory markers of inflamed paw or spinal cord. Anti-inflammatory properties of anti-Ly6G or LEC suggest that macrophages and/or neutrophil-mediated inflammatory cascade in inflamed site and spinal cord which can play key roles in inflammatory pain responses. These systemic or peripheral inflammatory mediators may be therapeutic targets in the treatment of many inflammatory conditions and related various diseases.

Effects of silica nanoparticles on isolated rat uterine smooth muscle.

In spite of their widespread use, toxicity of silica nanoparticles (SiO2 NPs) to mammalian has not been extensively investigated. In the present study, it is aimed to investigate the effects and the mechanism of action of 20 nm sized SiO2 NPs on isolated uterine smooth muscle. A total number of 84 preparations of uterine strips were used in the experiments. Study was designed as four groups: group I (control), group II (0.2 mM SiO2 NPs), group III (0.4 mM SiO2 NPs) and group IV (0.8 mM SiO2 NPs). Spontaneous contractions were recorded using mechanical activity recording system. Superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities and malondialdehyde (MDA) levels were measured using the spectrophotometric methods. Apoptosis of the cells was detected using immunofluorescence staining assay. SiO2 NP distribution and ultrastructural changes were determined by transmission electron microscopy. In groups II-IV, the frequency of contraction was significantly lower than that of the group I, whereas the contraction energy significantly decreased only in group IV. SOD and GSH-Px activities were significantly lower in experimental groups compared to the control group. MDA level and apoptotic cells were significantly higher in all SiO2 groups compared to the control group. Numerous SiO2 NPs in cytoplasm and connective tissue were observed in all dose groups. These findings showed that 20 nm sized SiO2 NPs enter the connective tissue and cytoplasm of uterine muscle cells and cause oxidative stress and apoptosis leading to impaired uterine contractile activity.

Expression of ER stress markers (GRP78 and PERK) in experimental nephrotoxicity induced by cisplatin and gentamicin: roles of inflammatory response and oxidative stress.

This study aimed to establish the relationship between two endoplasmic reticulum (ER) stress proteins, glucose-regulated protein 78 (GRP78/BiP) and PKR-like endoplasmic reticulum kinase (PERK), and oxidative stress markers in cisplatin (CIS)-induced and gentamicin (GEN)-induced nephrotoxicity.The study consisted of five groups: control (saline solution only), CIS D2 (2.5 mg/kg for 2 days), CIS D7 (2.5 mg/kg for 7 days), GEN D2 (160 mg/kg for 2 days), and GEN D7 (160 mg/kg for 7 days). All rats were sacrificed 24 h after the last injection for standard clinical chemistry, and ultrastructural and histological evaluation of the kidney.CIS and GEN increased blood urea nitrogen (BUN) and serum creatinine (Cr) levels, as well as total oxidant status (TOS), while decreasing total antioxidant status (TAS) level in CIS D7 and GEN D7 groups. Histopathological and ultrastructural findings were also consistent with renal tubular damage. In addition, expression of markers of renal inflammation (tumor necrosis factor-α (TNF-α) and interleukin 1ß (IL-1ß)) and ER stress markers (GRP78 and PERK) was significantly increased in the kidney tissue of rats treated with CIS and GEN for 7 days.These findings suggest that CIS and GEN administration for 7 days aggravates nephrotoxicity through the enhancement of oxidative stress, inflammation, and ER stress-related markers. As a result, the recommended course of action is to utilize CIS and GEN as an immediate but brief induction therapy, stopping after 3 days and switching to other drugs instead.

Pulsed magnetic field treatment ameliorates the progression of peripheral neuropathy by modulating the neuronal oxidative stress, apoptosis and angiogenesis in a rat model of experimental diabetes.

OBJECTIVE: The present study aimed to investigate the possible anti-neuropathic effects of daily pulsed magnetic field treatments (PMF) in streptozotocin (60 mg/kg) induced 4 weeks diabetic (type-1) wistar rats (6-8 months). MATERIALS AND METHODS: Body mass, blood glucose and thermal and mechanical sensations were evaluated during the PMF or sham-PMF in diabetic or non-diabetic rats (n = 7/group). After the measurements of motor nerve conduction velocities (MNCV), the levels of several biomarkers for oxidative stress, apoptosis and angiogenesis in spinal cord and sciatic nerve were measured. RESULTS: PMF for 4 weeks significantly recovered the MCNV (96.9% and 63.9%) and almost fully (100%) restored to the latency and threshold. PMF also significantly suppressed the diabetes induced enhances in biochemical markers of both neuronal tissues. CONCLUSIONS: Findings suggested that PMF might prevent the development of functional abnormalities in diabetic rats due to its anti-oxidative, anti-apoptotic and anti-angiogenic actions in neuronal tissues.

Neuroprotective and anti-neuropathic actions of pulsed magnetic fields with low frequencies in rats with chronic peripheral neuropathic pain.

The management of chronic peripheral neuropathic pain conditions with conventional treatments is still limited. In this present study, we aimed to determine the anti-neuropathic actions of pulsed magnetic field (PMF) treatments as a therapeutic. Effects of daily PMF treatments for 4 weeks were investigated by examining pain behaviors, hyperalgesia and allodynia, electrophysiological parameters, amplitude of compound action potential (CAP) and sciatic nerve conduction velocity (SNCV) and histopathological changes in rats with chronic constriction injury (CCI). Peripheral and central pro-inflammatory cytokines (TNF α, IL-1ß and IL-17), chemokines (CCL3 and CXCL1) and angiogenic factors (VEGF and bFGF) in sciatic nerves and spinal cord tissues were also measured for determining the possible molecular action mechanisms of PMF treatment. Hyperalgesia and allodynia were observed at the first week and lasted for 4 weeks after CCI. PMF treatments caused time-dependent anti-hyperalgesic and anti-allodynic effects. PMF treatment alleviated the histopathological consequences of CCI on sciatic nerve and significantly improved the amplitude of the CAP and SNCV. PMF treatment inhibited the pro-inflammatory molecules and promoted the anti-inflammatory cytokines in neural tissues. PMF treatment also suppressed the VEGF levels and enhanced the bFGF levels in both neural tissues. The results of the present study suggested that daily PMF treatment may have neuroprotective and anti-neuropathic pain actions in rats with CCI-induced neuropathy due to its modulating effects on neuro-inflammatory and neuro-angiogenic mediators in central and peripheral neural tissues.

Pro-inflammatory or anti-inflammatory effects of pulsed magnetic field treatments in rats with experimental acute inflammation.

In this study, we evaluated the possible effects of sequenced pulsed magnetic fields (PMF) of 1-mT treatments with designed different frequencies (PMF-1-1, 3, 5, 7 Hz or PMF-2-7, 9, 12, 14 Hz) on the inflammatory signs such as abnormal pain behaviors, hyperalgesia and allodynia, edema, and fever in carrageenan (CG)-induced hind paw inflammation model in rats. Paw tissues were also histologically examined. PMF exposure was applied 3 times in 24 h. CG injection gradually decreased the thermal latencies and mechanical threshold and caused significant increases in temperature and mass of paw. PMF treatments significantly reduced the temperature and mass in the paw of rats with inflammation. PMF-1 treatments caused significant increases in the latencies and thresholds. However, administration of PMF-2 treatment was significantly decreased the latency and threshold. Furthermore, the histological pieces of evidence also suggested the anti-inflammatory effects of PMF-1 treatments or inflammatory actions of PMF-2 treatments. Findings presented in this paper suggest that 1-mT PMF treatments may have anti-edematous and antipyretics activities in inflamed rats. However, the effects of PMF treatments on abnormal pain hypersensitivities may be different. PMF treatments may make inflammatory pain relief or worse in inflamed rats depending on the PMF frequencies in sequence.

Effects of immune cell-targeted treatments result from the suppression of neuronal oxidative stress and inflammation in experimental diabetic rats.

In this study, we hypothesized that reduction of immune cell activation as well as their oxidant or inflammatory mediators with minocycline (MCN), liposome-encapsulated clodronate (LEC), or anti-Ly6G treatments can be neuroprotective approaches in diabetic neuropathy. MCN (40 mg/kg) for reduction of microglial activation, LEC (25 mg/kg) for of macrophage inhibition, or anti-Ly6G (150 µg/kg) for neutrophil suppression injected to streptozotocin (STZ)-induced diabetic rats twice, 3 days, and 1 week (half dose) after STZ. Animal mass and blood glucose levels were measured; thermal and mechanical sensitivities were tested for in pain sensations. The levels of chemokine C-X-C motif ligand 1 (CXCL1), CXCL8, and C-C motif ligand 2 (CCL2), CCL3, and total oxidant status (TOS) and total antioxidant status (TAS) were measured in the spinal cord and sciatic nerve tissues of rats. LEC significantly reduced the glucose level of diabetic rats compared with drug control. However, MCN or anti-LY6G did not change the glucose level. While diabetic rats showed a marked decrease in both thermal and mechanical sensations, all treatments alleviated these abnormal sensations. The levels of chemokines and oxidative stress parameters increased in diabetic rats. All drug treatments significantly decreased the CCL2, CXCL1, and CXCL8 levels of spinal cord tissues and ameliorated the neuronal oxidative stress compared with control treatments. Present findings suggest that the neuroprotective actions of MCN, LEC, or anti-Ly6G treatments may be due to the modulation of neuronal oxidative stress and/or inflammatory mediators of immune cells in diabetic rats with neuropathy.

Antiinflammatory properties of antiLy6G antibody disappear during magnetic field exposure in rats with carrageenan induced acute paw inflammation.

Antiinflammatory properties of pulsed magnetic field (PMF) treatments or administration of antiLy6G antibody have been previously reported. In this study, we hypothesized that, the combination of PMF treatments and antiLy6G administration may synergistically potentiate their antiinflammatory actions. The effects of the combination of PMF treatments and antiLy6G administration were investigated by examining the inflammatory signs, histopathological properties of the inflamed site, and measuring the macrophage inflammatory protein-1 alpha (MIP-1α/CCL3) and myeloperoxidase (MPO) levels of inflamed paw tissues in rats with carrageenan-induced acute paw inflammation. In this present study, PMF treatments alone or administration of antiLy6G alone ameliorated the acute inflammation. However, their combination exacerbated the inflammatory signs, hyperalgesia, allodynia, edema and fever, and aggravated the inflammatory conditions by excessive infiltration of inflammatory cells to the inflamed site. These opposing effects of the combined treatments may correlate with enhanced levels of MIP-1α and MPO in inflamed paws. Present results indicated that the combination of the PMF treatments and antiLy6G administration may not provide additional benefits and may actually cause an aggravation of the acute inflammatory process. Findings may also suggest that during neutrophil or immune cell-targeted treatments for inflammatory states, magnetic field exposure may cause unexpected negative consequences.

The effects of sacubitril/valsartan and ramipril on the male fertility in hypertensive rats.

OBJECTIVE: Renin angiotensinogen system (RAS) inhibitors, ramipril and sacubitril/valsartan are frequently used in the treatment of cardiovascular diseases. Although they are known as contraindicated during pregnancy in hypertensive women, there is not any outcome of their safety in male fertility after exposure to ramipril or sacubitril/valsartan. In this study, we aimed to evaluate the effects of ramipril and sacubitril/valsartan to highlight their safety in the male fertility in normotensive and hypertensive rats. METHODS: Adult male normotensive and dexamethasone-induced hypertensive rats were treated with sacubitril/valsartan, ramipril and saline for 18 days. Arterial blood pressures were verified using carotid artery cannulation. Male fertility parameters, including the testis weights, histopathologic scoring of the testis, sperm count, sperm motility, morphology, and serum testosterone levels, were analyzed in treated and nontreated normotensive/hypertensive rats. RESULTS: Sacubitril/valsartan or ramipril treatments did not reveal a significant difference in sperm production, testicular morphology, and radioimmunoassay of serum testosterone levels compared to the control group. However, sperm motility was significantly reduced in rats under RAS inhibition. CONCLUSION: This finding was likely mediated by the identification of Ang receptors in the tails of rat sperm given that Ang receptors may play a role in the modulation of sperm motility. Identification of RAS-related proteins involved in sperm motility may help to explain their roles in motility. Our data provide general safety evidence for the male fertilization ability after paternal sacubitril/valsartan and ramipril exposure.

Bisoprolol and linagliptin ameliorated electrical and mechanical isometric myocardial contractions in doxorubicin-induced cardiomyopathy in rats.

BACKGROUND: Doxorubicin is an anthracycline chemotherapeutic agent that causes cardiomyopathy as a side effect. Here, we aimed to investigate the effects of linagliptin and bisoprolol on the management of doxorubicin-induced cardiomyopathy in rats. METHODS: Wistar rats were divided into six groups (n = 8). Group I received saline for 4 weeks; group II received 1 mg/kg bisoprolol for 8 weeks; group III received 3 mg/kg linagliptin for 8 weeks; group IV received 1.25 mg/kg doxorubicin for 4 weeks for the induction of cardiomyopathy; group V received 1.25 mg/kg doxorubicin for 4 weeks plus 1 mg/kg bisoprolol for 8 weeks; and group VI received 1.25 mg/kg doxorubicin for 4 weeks plus 3 mg/kg linagliptin for 8 weeks. Electrocardiography and isometric mechanography were conducted to measure ventricular contractile responses. Myocardial tissue and serum samples were analyzed for oxidative and cardiotoxic markers by ELISA. RESULTS: Electrocardiography revealed that QRS, QT and Tp intervals were longer in group IV than group I. Doxorubicin caused a significant decrease in ventricular contraction, which was significantly prevented by bisoprolol. Doxorubicin resulted in myocardial fiber disorganization and disruption, but bisoprolol or linagliptin improved this myocardial damage. Glutathione peroxidase was significantly decreased in groups IV and V. Bisoprolol or linagliptin treatment attenuated the significant doxorubicin-mediated increase in malondialdehyde. Doxorubicin and linagliptin provided significant elevations in CK-MB activity and troponin-I levels. CONCLUSIONS: Doxorubicin resulted in pronounced oxidative stress. The beneficial effects of bisoprolol and linagliptin on myocardial functional, histopathological and biochemical changes could be related to the attenuation of oxidative load.

Angiotensin converting enzyme and neprilysin inhibition alter pain response in dexhamethasone-induced hypertensive rats.

BACKGROUND: We hypothesized that renin-angiotensin system and neprilysin (NEP) inhibition can modulate the nociceptive parameters on hypertensive rats. The aim of this study is to assess the preventive and therapeutic effects of ramipril and sacubitril on the pain hypersensitivities, and their interaction mechanisms with high blood pressure. METHODS: Antinociceptive effects of ramipril and sacubitril were compared with those of diclofenac. Threshold of pain assesments were recorded before drugs administration. After a 18 days treatment, normotensive and dexamethasone-induced hypertensive rats were evaluated on thermal hyperalgesia and mechanical allodynia tests. Blood pressure of rats were verified by mean arterial pressure measurement. RESULTS: Hypertensive rats showed significantly high pain threshold on thermal plantar test compared to that of normotensives. Among hypertensive rats, pain hypersensitivity was lowest in diclofenac group, followed by sacubitril group, while ramipril caused increased thermal and mechanical hypersensitivities. CONCLUSION: We found that NEP inhibition may play a role in nociception in hypertensive rats. NEP inhibitors may be suitable choice for the management of hypertension and pain because of their therapeutic and preventive effects on nociception and arterial blood pressure.

Pain-Relieving Effectiveness of Co-Treatment with Local Tramadol and Systemic Minocycline in Carrageenan-Induced Inflammatory Pain Model.

In this study, we tested our working hypothesis that inhibiting the activation of microglia by systemic minocycline treatments can decrease the dosage of local tramadol injection in inflammatory pain. This study was therefore aimed to evaluate the actions of intraplantarly injected tramadol, intraperitoneally injected minocycline, or their combined treatments on the inflammation-induced hypernociception (thermal hyperalgesia, mechanical allodynia), edema, and pro- and anti-inflammatory cytokine levels of paw and spinal cord tissues in a rat model of carrageenan-induced hindpaw inflammation. While local tramadol or systemic minocycline caused a significant anti-hypernociceptive effect their combined treatments significantly enhanced anti-hypernociceptive action compared to each agent applied alone. Also anti-edematous actions of combined treatment were higher than that of their individual administrations. In addition, combined treatment significantly decreased the level of the pro-inflammatory cytokines and caused significant increases in anti-inflammatory cytokine level of paw and spinal cord tissues. The present finding can suggest that combined treatments of local tramadol and systemic minocycline may decrease the dose requirements for anti-hypernociceptive actions of local tramadol and this combination therapy might be a beneficial option for the inflammatory pain relief.

N-Acetylcysteine-induced vasodilatation is modulated by KATP channels, Na+/K+-ATPase activity and intracellular calcium concentration: An in vitro study.

BACKGROUND: In this study, we aimed to investigate the role of ATP-sensitive potassium (KATP) channel, Na+/K+-ATPase activity, and intracellular calcium levels on the vasodilatory effect of N-acetylcysteine (NAC) in thoracic aorta by using electrophysiological and molecular techniques. METHODS: Rat thoracic aorta ring preparations and cultured thoracic aorta cells were divided into four groups as control, 2mM NAC, 5mM NAC, and 10mM NAC. Thoracic aorta rings were isolated from rats for measurements of relaxation responses and Na+/K+-ATPase activity. In the cultured thoracic aorta cells, we measured the currents of KATP channel, the concentration of intracellular calcium and mRNA expression level of KATP channel subunits (KCNJ8, KCNJ11, ABCC8 and ABCC9). RESULTS: The relaxation rate significantly increased in all NAC groups compared to control. Similarly, Na+/K+- ATPase activity also significantly decreased in NAC groups. Outward KATP channel current significantly increased in all NAC groups compared to the control group. Intracellular calcium concentration decreased significantly in all groups with compared control. mRNA expression level of ABCC8 subunit significantly increased in all NAC groups compared to the control group. Pearson correlation analysis showed that relaxation rate was significantly associated with KATP current, intracellular calcium concentration, Na+/K+-ATPase activity and mRNA expression level of ABCC8 subunit. CONCLUSION: Our findings suggest that NAC relaxes vascular smooth muscle cells through a direct effect on KATP channels, by increasing outward K+ flux, partly by increasing mRNA expression of KATP subunit ABCC8, by decreasing in intracellular calcium and by decreasing in Na+/K+-ATPase activity.